“My fear is that one day someone may die in a police car while on the way to hospital because an ambulance is not available.

“There clearly needs to be better management within the NHS so that vehicles aren’t tied up waiting at hospitals.”

In the 2013-14 financial year, 19 patients in North Wales were taken to hospital by police cars.

Across Wales, cases involving people transported by police cars included falls in the street, attempted suicide, head injuries, stabbings, overdoses, self-harm and hypothermia.

In South Wales, the number of people taken to hospital by police car more than doubled from 83 in 2012-13 to 187 in the last financial year. There were 51 recorded in the Gwent force area in 2013-14.

Between April 2011 and April this year, there were 199 cases of police cars taking people to hospital in Gwent and 342 cases in South Wales.

Dyfed Powys Police said it was too costly to provide the information.

Mrs Jones added: “There clearly needs to be better management within the NHS so that vehicles aren’t tied up waiting at hospitals.

“For too long the ambulance service hasn’t been given enough priority by the Welsh Government.”

Mike Collins, director of service delivery at the Welsh Ambulance Service, said: “The trust is working in partnership with police forces across Wales to reduce instances where our emergency colleagues are awaiting an ambulance response.

“Both the trust and all four police forces maintain frequent contact and are building on the close relationship in support of each other and their staff.”

Mr Collins added hie organisation was working to get to patients as quickly as possible and it was seeing an improvement in response figures.

He said handover delays were of particular concern, but the service had been successful with new ways of minimalising them.